1. Field of the Invention
The present invention relates to a swing machine having a dial which is operated to select and indicate a pattern to be stitched.
2. Prior Art
Recently, the sewing machine has come to have a lot of patterns stored therein as programmed under control of a computer such that the patterns may be optionally selected to form an optional combination of patterns or to form embroidery patterns. The selected pattern or patterns may be indicated in an electronic indicator including liquid crystal and may be visually confirmed prior to starting stitching operation, and thus the errors in stitching operation may be prevented.
It is generally known that the sewing machine has a pattern selecting means, for example, such as a dial operation type, a touch switch type, a numeral input type and so on. The pattern selecting means of a touch switch type or a numeral input type is generally so formed as to electrically control the production of patterns which are selected normally in a computer controlled sewing machine. The pattern selecting means of a dial operation type is disclosed, for example, in the Japanese patent laid open No. 50-133051. This pattern selecting means includes pattern cams which may be optionally selected by operation of a dial normally in a mechanically controlled sewing machine.
In the recent years, the switches of electronic parts such as a push button, a touch panel and the like are often used in computerization of sewing machine. However it must be recognized that these electronic Switches are something alien to the machine users who have long been accustomed to a specific operation, for example, in the mechanically controlled sewing machines. Namely, it is a fact that the dial operation type as disclosed, for example, in the Japanese patent laid open No. 50-133051 is familiar to the machine users.
As to the pattern selecting means of dial operation type, a device has been proposed, wherein a dial is rotated to detect the rotation quantity which is used to designate a pattern information, or a dial is rotated to detect the angular position which is converted to an electric signal for indicating a pattern information at an indicator. Such pattern selecting means may be employed in a mechanical pattern producing device or in a computer controlled pattern producing device.
However, the pattern selecting means of dial operation type is generally of a photo-detecting system or of a magnetic detecting system. The mechanism is, therefore, rather complex and expensive. Especially in case the number of patterns is increased, the angular region to be detected per pattern is necessarily narrow in pattern selection, and the errors may easily happen in selection of pattern and/or in operation of the dial. Thus the pattern selecting means of dial operation type is mechanically unsuitable for selection of increased number of patterns.